Carton-bottom locking machine



ly 1955 E. M. MlSCHKE 2,713,812

CARTON-BOTTOM LOCKING MACHINE Filed March 20, 1955 2 Sheets-Sheet l INVEN TOR.

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CARTON-BOTTOM LOCKING MACHINE July 26, 1955 Filed March 20, 1953 2Sheets-SheetZ I N V EN TOR.

BY Z 6 Z 'wmm CARTGN-BOTTQM LUCKING MACHINE Edward M. Mischke, Appleton,Wis., assignor to Marathon @orporation, Rothschild, Wis., a corporationof Wisconsin Application March Zil, 1953, Serial No. 343,590

3 Claims. (Cl. 93-36) This invention relates to machines forfacilitating the folding and interlocking of the closure flap of acarton or container. The invention is particularly adapted for use withcorrugated paperboard cartons or boxes, but may also be used for thefolding and interlocking of the closure flaps of boxes made from othertypes of paperboard or similar material.

These cartons or boxes are used in extremely large quantities for thepackaging of products for retail sale, for transport, for storage andthe like. Because the use is ordinarily in a mass-production quantity,it is necessary that the manufacture and the set-up of the carton beaccomplished at the highest possible speed and with all other attainablefavorable features of economy. In order to save shipping expense, it ispreferable that the carton manufacturer assemble the carton in a flat orknockdown condition, before shipment to the manufacturer of the productto be packed in the carton, thereby reducing transportation cost. Amanufacturer of the product to be packaged must then be able to set upthe carton at a rapid rate for filling with the product to be packaged.This setting-up is frequently done by completely automatic machinery,but in other cases, particularly of the smaller volume productmanufacturers, such machinery would require an unwarranted expenditureso that the setting-up of the carton must at least to some extent be ahand operation.

My invention is of particular value to those product manufacturers who,due to relatively small volume or other reason, find it undesirable toinvest in the rather expensive automatic machinery, but rather must tosome extent accomplish the setting-up of the carton by hand operation.My invention provides an inexpensive machine which facilitates this handsetting-up operation, thus permitting a relatively rapid rate ofassembly even for the small manufacturer.

The objects and marked advantages of my invention will be apparent fromthe following description and the accompanying drawings, in which:

Figure l is a perspective view of my machine for interlocking theclosure flaps of a carton, I

Figure 2 is a perspective view of a carton particularly adapted for usewith my invention, with the bottom of the carton in open position,

Figure 3 is a perspective view of the carton shown in Figure 2, with thecarton in the collapsed position in which it is customarily shipped fromthe carton manufacturer to the packer of the product to be contained,

Figure 4 is a perspective view similar to Figure 2, showing an initialstage of the closing operation of the bottom of the carton, I

Figure 5 is a side elevation, partially cut away, of the carton ofFigure 4 being acted upon by my invention to close the bottom of thecarton,

Figure 6 is a side elevation, partially cut away, similar to Figure 5,showing a further stage of the bottom closing operation as effected bymy invention,

Figure 7 is another side elevation, partially cut away,

nited States Patent 0 ice similar to Figure 6, showing the final stageof the bottom closing operation,

Figure 8 is a perspective view showing the assembled carton,

Figure 9 is a side elevation of a modified form of my invention, withthe open carton shown in phantom lines thereon in position for thebottom-closing operation,

Figure 10 is a detailed perspective view of a portion of the modifiedform of my invention illustrated in Figure 9, and

Figure 11 is a top perspective view of the assembled carton, with aseparate bottom or end wall which might be inserted internally toprovide a more secure bottom or end, and which may be advantageouslyincluded in the bottom or end closing operation.

Referring first to Figure 1, it is seen that my invention comprises abase or anchor plate 1 to which are rigidly secured by any suitablemeans four spaced, perpendicularly-disposed columns or standards 2. Atop plate 3 is rigidly secured atop these upright columns 2 by anysuitable means such as screws 4. Compression springs 5 encircle each ofcolumns 2 and are supported at their lower ends against base plate 1. Ifdesired, springs 5 may be secured firmly at their lower ends to baseplate 1, but this is not essential.

Columns 2 extend through holes 6 in each corner of a rectangularfloating plate 7, this plate resting against the upper ends ofcompression springs 5 and being resistably supported thereby. Ifdesired, plate 7 could be fixed to the upper ends of springs S, but thisis not essential.

Figure 2 illustrates a carton particularly adapted for operation with myinvention, showing the open end or bottom of the carton with the end orbottom flaps extending. It. is immaterial Whether this open portion ofthe carton be considered the end or the bottom, this depending merelyupon the attitude and use of the carton, but for the purposes of thisdescription will be considered the bottom. The carton comprises sidewalls 10, 11, 12 and 13, hingedly connected together at their sideedges, and having bottom flaps 14, 15, 16 and 17 hingedly connected totheir respective bottom edges.

Spaced inwardly of the side edges of each of bottom flaps 14 and 16 is apair of spaced cut-outs or slots 29, and similarly spaced intermediatethe side edges of each of bottom flaps 15 and 17 is a pair of cut lines21. Score lines 22 connect the inner ends of the pairs of cut lines 21.A. portion of the opposite ends of the side walls of the carton may befolded or rolled back, if desired, to produce a reinforcing double-endtop as at 23.

The bottom-closing operation, as facilitated by my invention, may now bedescribed. The carton which is to be filled with the particular productis ordinarily received from the carton manufacturer in a conditionillustrated in Figure 3, wherein the carton is collapsed for shipment inthe flat condition in order to reduce the transportation expense.

The collapsed carton as shown in Figure 3 may be pressed by hand atopposite side edges 24 to open the carton and square it into theposition substantially as shown in Figure 2. The thus-squared carton isthen placed over the top plate 3 of my machine, with the reinforced end23 of the carton down, and dropped down over my machine until thisreinforced end rests on spring-supported floating plate 7, asillustrated in Figure 4. As seen in Figure 4, bottom flaps l4 and 16 arethen folded inwardly, which causes alignment of opposing pairs of slots20 in those two flaps. Locking tabs 25, which are defined by cut lines21 and score lines 22 in bottom flaps 15 and 17, are then foldedinwardly about the hinge connection of score lines 22 and their outeredges initially inserted into the space provided by the respectivelyadjacent opposed pairs of slots 29 (see also Figure 5),

With both of locking tabs 25 inserted in the respective slots 20, handpressure may be applied to bottom flaps 15 and 17 just below score lines22, as seen in Figure 5. As this pressure is applied, locking tabs 25are depressed further into slots 20, and springs are partiallycompressed by the force applied against floating plate 7 bearing theweight of the carton and the applied pressure, permitting the bottom ofthe carton as indicated by bottom flaps 14 and 16 in Figure 6 to movedownward and closer to top plate 3. With the continuation of the handpressure, the locking tabs 25 enter the slots 20 completely, permittingbottom flaps 15 and 17 to closely overlie bottom flaps 14 and 16, and asthe bottom of the carton is pressed down into close relationship withtop plate 3, locking tabs 25 are forced inwardly and toward each otherto lie fiat againsdt the inner surfaces of bottom flaps 14 and 16intermediate slots 20.

As will be noted particularly from Figure 6, hinge lines 22 lie veryslightly outwardly of the entrances formed by the opposed pairs of slots20, thus assuring that locking tabs 25 will be directed inwardly of thecarton bottom. In actual operation, this bottom set-up operation can beaccomplished in a rapid fashion, by applying a sudden pressure to bottomflaps 15 and 17 after the carton has been placed on the machine as shownbest in Figure 5. A uniformly strong bottom closure will result as shownin Figure 8, with a requirement of relatively little effort and set-uptime, as is desirable if this type of carton is to find commercialsuccess with the relatively small product manufacturer who cannot availhimself of automatic set-up machinery.

From the foregoing description, it will be obvious that my invention maypermit of several modifications, and that the essential feature isrelative movement between plate 3 and plate 7. Whether floating plate 7moves downwardly under pressure, or on the other hand top plate 3 movesupwardly while plate 7 and the carton are restrained, is immaterial, theonly requirement being that these plates move relative to each otherwith gravity or other resistance in opposition to such motion as themotion tends to separate them. For example, tension springs connectedbetween plates 3 and 7 might readily be substituted for compressionsprings 5.

Figure 9 shows a second method of achieving the necessary operation ofmy invention. Arms 30 are pivotally connected to columns 2a as at 31 andare resistably held outwardly at an inclination to columns 2a bycompression springs 32 interposed between arms 30 and columns 2a. Theouter ends of arms 30 carry rotatable rollers 33.

In this second embodiment of my invention, arms 30 fill the purposeserved by supporting plate '7 in my first embodiment, that is they areso resistably inclined as to contact the reinforced top end 23 of thecarton when it is inserted over the top plate 3a. As pressure is appliedto set up the bottom of the carton, in a manner similar to thatpreviously described, arms 30 are forced to pivot downwardly about theirpivot points 31, overcoming the opposition of compression springs 32,permitting carton to ride downwardly as pressure is applied to performthe set-up operation. Rollers 33 permit the withdrawal of the cartonafter the bottom has been set up without substantial resistance from thepressure of the arms 31 against the side walls of the carton.

Figure shows the previously set-up carton with a separate reinforcingbottom 43 which may be inserted internally of the carton to lie flatagainst locking tabs 25 and bottom flaps 14 and 16. When the carton isfilled with the product to be packaged, this bottom, since it lies fiatagainst internally-extending locking tabs 25, serves to reinforce thelocked position of the bottom of the carton. This reinforcing bottom 40may be inserted after the carton is formed as previously described, orit may be placed in position prior to the actual settingup of the bottomof the carton on my machine. In such latter event, the first step in thesetting-up operation is to place the bottom 40 upon top plate 3, andthen to place the carton upon my machine as previously described andcarry out the setting-up operation as stated above. The reinforcingbottom 40 in such event merely serves as an extra layer atop top plate3, and in no way interferes with the operation of my machine. if thereinforcing bottom 40 is cut to fit rather snugly inside the finishedcarton, there will be no tendency of it to stay on top of top plate 3when the set-up carton is removed from the machine, but ratherfrictional force will maintain the reinforcing bottom 40 in the bottomof the carton.

Other modifications of my invention may be made without departing fromthe spirit of my invention. It is therefore to be understood that nolimitations are to be imposed upon my invention except as arespecifically set forth in the following claims.

I claim:

1. A carton-bottom locking machine, the carton comprising opposed pairsof side walls, opposed pairs of bottom flaps connected to the bottom endedges of said side Walls, an opposed pair of said bottom flaps havinglocking tabs hinged thereto, the other pair of said flaps having slotsfor interlocking engagement with said tabs when said tabs are insertedinternally of the carton through the slots, said machine including afixed plate adapted to be positioned within said carton below the bottomthereof in carton-inverted position, a plurality of spaced columnssupporting said plate in fixed position, a yieldable plate upon whichthe top of said inverted carton rests in carton-supporting position andadapted to yieldably resist relative movement of the bottom of saidinverted carton toward said fixed plate, said yieldable plate containinga plurality of holes through which said columns are disposed forguidance of the yieldable plate in slidable relationship, and aplurality of compression springs encircling said columns and supportedthereby below and in yieldable supporting relation with said yieldableplate, whereby when said inverted carton is pressed downwardly with saidtabs inserted through the slots against the force of said yieldableplate to make contact between said tabs and the fixed plate the bottomlock is thereby effected.

2. A carton-bottom locking machine, the carton comprising opposed pairsof side walls, opposed pairs of bottom flaps hinged to the bottom edgesof the side walls, one pair of said flaps having locking tabs hingedthereto, each flap of the other pair of said flaps having a pair ofspaced slots disposed intermediate of its side edges and extendinginwardly of the end edge thereof, said slots when the other pair offlaps are folded inwardly to close the bottom of the carton beingaligned in opposing pairs to form two spaced slots disposed centrally ofthe thus-closed carton bottom, said locking tabs being disposed to entersaid two spaced slots to form a locked carton-bottom closure, saidmachine including a plurality of fixed, upright, spaced columns, ayieldable plate containing a plurality of holes through which saidcolumns are slidably disposed, said yieldable means being adapted tosupportably contact the top edge of the carton in carton-invertedposition for I yieldable support thereof, compression springs encirclingsaid columns below said yieldable plate for yieldable support thereof,and a plate fixed atop said columns and adapted to be disposed inwardlyof the inverted carton below the bottom thereof, whereby said invertedcarton with the locking tabs inserted through said two spaced slots maybe pressed downwardly against the yieldable supporting force of saidyieldable plate to establish contact between said tabs and the fixedplate and thereby press the tabs against the inner surfaces of saidother pair of bottom flaps to effect the locked carton-bottom closure.

3. The method of machine-locking the bottom of a carton, the cartoncomprising opposed pairs of side walls, opposed pairs of bottom flapsconnected to the bottom end edges of the side walls, one opposed pair ofsaid bottom fiaps having locking tabs hinged thereto, and the other pairof said flaps having slots for interlocking engagement with said tabswhen the tabs are inserted internally of the carton through the slots,the machine including fixed first means and yieldable second meansdisposed below said first means a distance substantially less than theheight of the carton, the method comprising inverting the carton oversaid first means with the top of the carton resting on the yieldablesecond means, folding said other pair of flaps over the open bottom endof the carton to effect a closure, folding said one pair of flapsinwardly over the folded other pair, inserting the remote free ends ofsaid tabs into said slots, and pressing downwardly on said one opposedpair of bottom flaps to force the tabs through the slots and thereafterwith continued pressure force the carton downwardly against saidyieldable means to contact the ends of the tabs against said first meansto position the tabs flat against the bottom of the carton internallythereof to thereby effect the bottom lock.

References {lites} in the file of this patent UNITED STATES PATENTS1,193,934 Simpson Aug. 8, 1916 2,024,201 Benoit et al. Dec. 17, 19352,337,125 Page Dec. 21, 1943 2,505,703 Benoit et a1 Apr. 25, 1950

